Introduction: Rainwater Collected in Surface Water Bodies

In principle, the deliberate discharge of collected stormwater from built-up or paved areas into a surface water body constitutes a use of water within the meaning of the Water Resources Act (WHG), which requires a permit under water law. To this end, the relevant application documents must be submitted to the Office for Environmental Protection and Energy Issues.

Under certain conditions, discharge into surface waters is permitted without a permit within the framework of public use pursuant to the Bavarian Water Act (BayWG). In such cases, the “Technical Rules for the Harmless Discharge of Collected Stormwater into Surface Waters (TRENOG)” must be followed. A basic prerequisite is that infiltration is not possible or is only possible at great expense.

In connection with any discharge, the Office for Environmental Protection and Energy Issues/Water Protection must always verify whether the water body has sufficient capacity to prevent overflow or flooding. Depending on the type of water body and the source of the stormwater, treatment facilities are required prior to discharge to protect the water body from contamination. Stormwater treatment facilities must be regularly maintained to ensure they function properly.

Further information on this topic is available from the Office for Environmental Protection and Energy Issues/Water Protection.

Links:

BEN Program – Assessment of Whether Stormwater Discharges Are Exempt from Permits

Permit-Exempt Discharge of Collected Stormwater into Surface Waters – Technical Rules for the Harmless Discharge of Collected Stormwater into Surface Waters (TRENOG)